Wafer chamfering method and apparatus

Abstract

A wafer to be chamfered is supported in such a manner as to rotate and to move in the X-axis direction and the Y-axis direction which are perpendicular to one another, and a periphery grinding wheel is rotatably placed on the Y-axis. To chamfer a circular part of the wafer, the circular part of the wafer is pressed against the rotating periphery grinding wheel, and then, the wafer is rotated. To chamfer an orientation flat of the wafer, the orientation flat of the wafer is pressed against the rotating periphery grinding wheel, and then, the wafer is fed in the X-axis direction.

We claim: 
     
       1. A wafer chamfering method for chamfering a periphery of a wafer which has a circular part, an orientation flat part and orientation flat corner parts, wherein the wafer is supported in such a manner as to rotate and to move in an X-axis direction and a Y-axis direction which are perpendicular to one another in a horizontal plane, a periphery grinding wheel is rotatable about a vertical axis which intersects the Y-axis, said wafer chamfering method comprising the steps of: chamfering the circular part of the wafer by bringing the circular part along the Y-axis into contact with said periphery grinding wheel which is rotating, and by rotating the wafer;   chamfering the orientation flat part of the wafer by bringing the orientation flat part along the Y-axis into contact with said periphery grinding wheel which is rotating, and by feeding the wafer in the X-axis direction; and   chamfering one of the orientation flat corner parts of the wafer by bringing the one of the orientation flat corner parts into contact with said periphery grinding wheel, which is rotating, and by rotating the wafer and feeding the wafer in the X-axis direction and the Y-axis direction so that the one of the orientation flat corner parts can always be in contact with said periphery grinding wheel.   
     
     
       2. A wafer chamfering apparatus for chamfering a periphery of a wafer which has a circular part, an orientation flat part and orientation flat corner parts, said wafer chamfering apparatus comprising: a wafer table support which is capable of moving in an X-axis direction and a Y-axis direction which are perpendicular to one another in a horizontal plane;   a wafer table which is rotatably placed on said wafer table support and holds the wafer;   a grinding tool support which is positioned on the Y-axis and is capable of moving up and down perpendicular to said Y-axis;   a periphery grinding wheel which is rotatably placed on said grinding tool support;   a controller which controls feeding of said wafer table support in the X-axis direction and the Y-axis direction, rotation of said wafer table, up-and-down movement of said grinding tool support, and rotation of said periphery grinding wheel;   wherein said controller brings the circular part of the wafer along the Y-axis into contact with said periphery grinding wheel, which is rotating, and rotates the wafer, thereby chamfering the circular part;   said controller brings the orientation flat part of the wafer along the Y-axis into contact with said periphery grinding wheel, which is rotating, and feeds the wafer in the X-axis direction, thereby chamfering the orientation flat part; and   said controller brings one of the orientation flat corner parts of the wafer into contact with said periphery grinding wheel, which is rotating, and rotates the wafer and feeds the wafer in the X-axis direction and the Y-axis direction so that the one of the orientation flat corner parts can always be in contact with said periphery grinding wheel, thereby chamfering the one of the orientation flat corner parts.   
     
     
       3. A wafer chamfering method for chamfering a periphery of a wafer which has a circular part, a notch part and notch corner parts, wherein the wafer is supported in such a manner as to rotate and to move in an X-axis direction and a Y-axis direction which are perpendicular to one another in a horizontal plane, a periphery grinding wheel and a notch grinding tool are rotatable about a vertical axis which intersects the Y-axis, said wafer chamfering method comprising the steps of: chamfering the circular part of the wafer by bringing the circular part along the Y-axis into contact with said periphery grinding wheel, which is rotating, and by rotating the wafer;   chamfering the notch part of the wafer by bringing the notch part along the Y-axis into contact with said notch grinding tool, which is rotating, and by feeding the wafer in the X-axis direction and the Y-axis direction so that the notch part can always be in contact with said notch grinding tool; and   chamfering one of the notch corner parts of the wafer by bringing the one of the notch corner parts alone the Y-axis into contact with said notch grinding tool, which is rotating, and by feeding the wafer in the X-axis direction and the Y-axis direction so that the one of the notch corner parts can always be in contact with said notch grinding tool.   
     
     
       4. A wafer chamfering apparatus for chamfering a periphery of a wafer which has a circular part, a notch part and notch corner parts, said wafer chamfering apparatus comprising: a wafer table support which is capable of moving in an X-axis direction and a Y-axis direction which are perpendicular to one another in a horizontal plane;   a wafer table which is rotatably placed on said wafer table support and holds the wafer;   a grinding tool support which is positioned on the Y-axis and is capable of moving up and down perpendicular to said Y-axis;   a periphery grinding wheel which is rotatably placed on said grinding tool support;   a notch grinding tool which is rotatably placed on said grinding tool support;   a controller which controls feeding of said wafer table support in the X-axis direction and the Y-axis direction, rotation of said wafer table, up-and-down movement of said grinding tool support, rotation of said periphery grinding wheel, and rotation of said notch grinding tool;   wherein said controller brings the circular part of the wafer along the Y-axis into contact with said periphery grinding wheel, which is rotating, and rotates the wafer, thereby chamfering the circular part;   said controller bring the notch part of the wafer along the Y-axis into contact with said notch grinding tool, which is rotating, and feeds the wafer in the X-axis direction and the Y-axis direction so that the notch part can always be in contact with said notch grinding tool, thereby chamfering the notch part; and   said controller brings one of the notch corner parts of the wafer along the Y-axis into contact with said notch grinding tool, which is rotating, and feeds the wafer in the X-axis direction and the Y-axis direction so that the one of the notch corner parts can always be in contact with said notch grinding tool, thereby chamfering the one of the notch corner parts.